In a statement, the State Department said such an attack would "constitute a direct and grave violation" of the agreement reached between Hamas and Israel to end the two-year war.

"Should Hamas proceed with this attack, measures will be taken to protect the people of Gaza and preserve the integrity of the ceasefire," the State Department said.

No details of the imminent attack were given.

President Trump previously warned that "if Hamas continues to kill people in Gaza, which was not the Deal, we will have no choice but to go in and kill them."

Trump later added that US troops would not be sent into Gaza.

"It's not going to be us," he told reporters.

"We won't have to. There are people very close, very nearby that will go in and they'll do the trick very easily, but under our auspices."

Note: There are currently social-media reports that the ceasefire has been broken and that Israel has resumed attacks on the Gaza Strip in response. We will provide updates as soon as they are available.